Item CA033003: The DNA sequence of similar genes in different organisms can differ at certain locations because of mutations that occur in those genes.
Dogs, pigs, and cats have similar genes for traits that they have in common, such as four legs, tails, and a rib cage. One of those genes, Gene X, is pictured above. Why does the DNA sequence of Gene X differ in some positions (highlighted in red) for dogs, pigs, and cats?
- Over time, the organisms’ traits changed, which caused Gene X to change.
- Over time, mutations occurred in Gene X.
- All three organisms had different needs, so they intentionally created different genes.
- Not enough information is given.
Pre-Test
Answer Choice |
Overall |
Grades |
Gender |
Primary Language |
||||
|---|---|---|---|---|---|---|---|---|
| n = 580 |
6–8 n = 25 |
9–12 n = 514 |
Male n = 254 |
Female n = 286 |
English n = 526 |
Other n = 13 |
||
| A. | Over time, the organisms’ traits changed, which caused Gene X to change. | 30% | 32% | 30% | 29% | 31% | 30% | 46% |
| B. | Over time, mutations occurred in Gene X. | 31% | 32% | 31% | 34% | 30% | 31% | 15% |
| C. | All three organisms had different needs, so they intentionally created different genes. | 31% | 32% | 30% | 31% | 30% | 31% | 23% |
| D. | Not enough information is given. | 8% | 4% | 8% | 7% | 9% | 8% | 15% |
Post-Test (Control)
Answer Choice |
Overall |
Grades |
Gender |
Primary Language |
||||
|---|---|---|---|---|---|---|---|---|
| n = 255 |
6–8 n = 15 |
9–12 n = 195 |
Male n = 97 |
Female n = 119 |
English n = 205 |
Other n = 6 |
||
| A. | Over time, the organisms’ traits changed, which caused Gene X to change. | 25% | 13% | 25% | 30% | 22% | 25% | 50% |
| B. | Over time, mutations occurred in Gene X. | 42% | 67% | 39% | 47% | 36% | 42% | 17% |
| C. | All three organisms had different needs, so they intentionally created different genes. | 25% | 7% | 27% | 15% | 31% | 23% | 33% |
| D. | Not enough information is given. | 8% | 13% | 9% | 7% | 11% | 9% | 0% |
Post-Test (Treatment)
Answer Choice |
Overall |
Grades |
Gender |
Primary Language |
||||
|---|---|---|---|---|---|---|---|---|
| n = 301 |
6–8 n = 8 |
9–12 n = 274 |
Male n = 134 |
Female n = 150 |
English n = 274 |
Other n = 9 |
||
| A. | Over time, the organisms’ traits changed, which caused Gene X to change. | 25% | 0% | 26% | 21% | 25% | 25% | 22% |
| B. | Over time, mutations occurred in Gene X. | 52% | 75% | 51% | 51% | 53% | 52% | 33% |
| C. | All three organisms had different needs, so they intentionally created different genes. | 21% | 25% | 21% | 25% | 19% | 20% | 44% |
| D. | Not enough information is given. | 3% | 0% | 3% | 3% | 3% | 3% | 0% |